function Map(ele) {
    this.ele = ele
    this.width = 800
    this.height = 400
}
Map.prototype.create = function() {
    this.ele.style.width = this.width + 'px'
    this.ele.style.height = this.height+ 'px'
    this.ele.style.background = 'url(./bg.png)'
    this.ele.style.border = '10px solid blue'
    this.ele.style.position='relative'
}